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Re: Hovercraft B/C
Posted: March 7th, 2018, 8:13 am
by mattruff
Do we have to have shielding for the fan blades on the bottom of our hovercraft if we don't have an inflated skirt?
Re: Hovercraft B/C
Posted: March 7th, 2018, 8:40 am
by antoine_ego
mattruff wrote:Do we have to have shielding for the fan blades on the bottom of our hovercraft if we don't have an inflated skirt?
Yeah you do. The rules state that you must have shielding even underneath the craft that prevents a 3/8 in dowel from touching it.
Re: Hovercraft B/C
Posted: March 7th, 2018, 12:16 pm
by mattruff
Does the inflated skirt on our hovercraft have to be clear?
Re: Hovercraft B/C
Posted: March 7th, 2018, 12:40 pm
by Tesel
mattruff wrote:Does the inflated skirt on our hovercraft have to be clear?
Not at all, it just has to be visible that the hovercraft is inflating. Lots of teams use black garbage bags and are perfectly fine.
Re: Hovercraft B/C
Posted: March 7th, 2018, 3:49 pm
by geniusjohn5
Has anyone tried using a centrifugal blower fan for lift? Like this one here?
https://www.mouser.com/ProductDetail/Sa ... sWEALw_wcB
If so, how did you guys mount it on your craft so it allows the hovercraft to hover adequately?
Re: Hovercraft B/C
Posted: March 7th, 2018, 4:54 pm
by cmurthy
Just wondering if a fan like the above also needs to be shielded since the blades are already inside the housing
Re: Hovercraft B/C
Posted: March 7th, 2018, 5:08 pm
by reed303
cmurthy wrote:
Just wondering if a fan like the above also needs to be shielded since the blades are already inside the housing
Typically the blades are covered on one side, but not the other, where air enters the blower. The "squirrel cage" is exposed. See the drawing at
https://www.mouser.com/ds/2/471/San_Ace ... 284362.pdf
From what I've seen, these blowers are mounted with the square outlet facing down, feeding the skirt, with the unit "standing up", parallel to the length of the craft.
Re: Hovercraft B/C
Posted: March 7th, 2018, 6:41 pm
by geniusjohn5
cmurthy wrote:
Just wondering if a fan like the above also needs to be shielded since the blades are already inside the housing
This type of fan most likely is going to be a lift fan so it will already be placed downward into the skirt, so there's no need for shielding if you're using it for lift. If you're using it for other purposes, I think shielding is needed, but I'm not sure.
Re: Hovercraft B/C
Posted: March 7th, 2018, 6:51 pm
by Tesel
geniusjohn5 wrote:cmurthy wrote:
Just wondering if a fan like the above also needs to be shielded since the blades are already inside the housing
This type of fan most likely is going to be a lift fan so it will already be placed downward into the skirt, so there's no need for shielding if you're using it for lift. If you're using it for other purposes, I think shielding is needed, but I'm not sure.
Actually, even though it is a lift fan, there is an open side for air intake that would need to be covered.
Re: Hovercraft B/C
Posted: March 7th, 2018, 8:36 pm
by EcoDyne
Given that the track width is much wider than the max width the hovercraft can be, does the hovercraft have to start in the exact center of the track? It isn't specificied in the rules, so does that mean we could start our hovercraft close to the sides so it keeps our hovercraft straight?
As my hovercraft had a tendency to not go straight, being able to start close to the walls means the difference between a successful and failed run. Is there an official statement about this or does it depend on the event supervisor at the event?